1. Field of the Invention
This invention relates to a method of manufacturing a commutator for an electric motor, and more particularly is directed to an improved method of manufacturing an electric motor commutator in which a plurality of commutator segments of copper or the like extend about the outer circumferential surface of a cylindrical insulator and are spaced apart by axially extending slots opening radially outward from the insulator between confronting surfaces of the adjacent segments.
2. Description of the Prior Art
In small-sized DC electric motors, such as are used for tape recorders, it is known to employ a commutator which includes a cylindrical insulator having an axial bore for receiving the rotary motor shaft, and a plurality of copper commutator segments which extend about the outer circumferential surface of the insulator and are spaced apart by axially extending slots opening radially outward from the insulator between confronting surfaces of the adjacent commutator segments. During operation of a DC electric motor of the described type, the friction between the commutator segments and the brushes engaging the same produces a conductive powder, for example, by erosion of the carbon brushes, and such conductive powder accumulates in the slots between the adjacent commutator segments. As a result of the accumulation of conductive powder in the slots, the insulation between the adjacent commutator segments deteriorates and the operating efficiency of the electric motor is decreased. Finally, the accumulated conductive powder in the slots may cause shorting of the adjacent commutator segments with the result that the useful life of the electric motor is curtailed.